This invention relates to magnetic cores and more particularly, to a machine for stacking the laminations of a magnetic core to provide a uniform stagger or offset.
As is well-known to those skilled in the magnetic core art, such as for example, the cores used in electrical magnetic induction apparatus, it is common to utilize a number of layers of electric grade magnetic core steel laminations which are formed to the desired shape of the core. In general, two methods are utilized in making such cores. The first method comprises the precutting of a sufficient number of separate laminations of appropriately increased length to form the desired core then stacking such laminations and finally forming them into the desired core. The second method generally comprises winding a single strip of magnetic material about a mandrel to form a roll or core having the desired number of laminations. The core is then cut and thereafter the cut laminations are offset to form the desired core. In most instances, the electromagnetic apparatus generally has a preformed coil and the core is cut and laced about the coil, in what is termed -- a lacing operation.
Also as is well-known to those skilled in the art, in making a magnetic core which is cut and placed around an electromagnetic coil it is necessary to offset or stagger the ends of the cut laminations from each other such that, the core losses will be reduced to a minimum. One example of such an offset core is found in U.S. Pat. No. 3,186,067, which issued June 1, 1965.
As is well-known to those skilled i- the art and is shown, for example by the above-mentioned U.S. Pat. No. 3,186,067, it is extremely difficult to provide a uniform overlapping of the cut ends of cores so as to minimize losses in the core as it is formed about the electromagnetic coil. Many different methods have been provided for offsetting the ends of the core laminations and it is to this particular field that this invention is addressed.